src/Pure/Tools/find_theorems.ML
author wenzelm
Fri Jul 01 16:05:38 2011 +0200 (2011-07-01)
changeset 43620 43a195a0279b
parent 43076 7b06cd71792c
child 43724 4e58485fa320
permissions -rw-r--r--
tuned layout;
     1 (*  Title:      Pure/Tools/find_theorems.ML
     2     Author:     Rafal Kolanski and Gerwin Klein, NICTA
     3 
     4 Retrieve theorems from proof context.
     5 *)
     6 
     7 signature FIND_THEOREMS =
     8 sig
     9   datatype 'term criterion =
    10     Name of string | Intro | IntroIff | Elim | Dest | Solves | Simp of 'term |
    11     Pattern of 'term
    12 
    13   datatype theorem =
    14     Internal of Facts.ref * thm | External of Facts.ref * term
    15 
    16   type 'term query = {
    17     goal: thm option,
    18     limit: int option,
    19     rem_dups: bool,
    20     criteria: (bool * 'term criterion) list
    21   }
    22 
    23   val tac_limit: int Unsynchronized.ref
    24   val limit: int Unsynchronized.ref
    25 
    26   val read_criterion: Proof.context -> string criterion -> term criterion
    27   val query_parser: (bool * string criterion) list parser
    28 
    29   val xml_of_query: term query -> XML.tree
    30   val query_of_xml: XML.tree -> term query
    31   val xml_of_result: int option * theorem list -> XML.tree
    32   val result_of_xml: XML.tree -> int option * theorem list
    33 
    34   val find_theorems: Proof.context -> thm option -> int option -> bool ->
    35     (bool * term criterion) list -> int option * (Facts.ref * thm) list
    36   val find_theorems_cmd: Proof.context -> thm option -> int option -> bool ->
    37     (bool * string criterion) list -> int option * (Facts.ref * thm) list
    38 
    39   val filter_theorems: Proof.context -> theorem list -> term query ->
    40     int option * theorem list
    41   val filter_theorems_cmd: Proof.context -> theorem list -> string query ->
    42     int option * theorem list
    43 
    44   val pretty_theorem: Proof.context -> theorem -> Pretty.T
    45   val pretty_thm: Proof.context -> Facts.ref * thm -> Pretty.T
    46 
    47 end;
    48 
    49 structure Find_Theorems: FIND_THEOREMS =
    50 struct
    51 
    52 (** search criteria **)
    53 
    54 datatype 'term criterion =
    55   Name of string | Intro | IntroIff | Elim | Dest | Solves | Simp of 'term |
    56   Pattern of 'term;
    57 
    58 fun apply_dummies tm =
    59   let
    60     val (xs, _) = Term.strip_abs tm;
    61     val tm' = Term.betapplys (tm, map (Term.dummy_pattern o #2) xs);
    62   in #1 (Term.replace_dummy_patterns tm' 1) end;
    63 
    64 fun parse_pattern ctxt nm =
    65   let
    66     val consts = Proof_Context.consts_of ctxt;
    67     val nm' =
    68       (case Syntax.parse_term ctxt nm of
    69         Const (c, _) => c
    70       | _ => Consts.intern consts nm);
    71   in
    72     (case try (Consts.the_abbreviation consts) nm' of
    73       SOME (_, rhs) => apply_dummies (Proof_Context.expand_abbrevs ctxt rhs)
    74     | NONE => Proof_Context.read_term_pattern ctxt nm)
    75   end;
    76 
    77 fun read_criterion _ (Name name) = Name name
    78   | read_criterion _ Intro = Intro
    79   | read_criterion _ IntroIff = IntroIff
    80   | read_criterion _ Elim = Elim
    81   | read_criterion _ Dest = Dest
    82   | read_criterion _ Solves = Solves
    83   | read_criterion ctxt (Simp str) = Simp (Proof_Context.read_term_pattern ctxt str)
    84   | read_criterion ctxt (Pattern str) = Pattern (parse_pattern ctxt str);
    85 
    86 fun pretty_criterion ctxt (b, c) =
    87   let
    88     fun prfx s = if b then s else "-" ^ s;
    89   in
    90     (case c of
    91       Name name => Pretty.str (prfx "name: " ^ quote name)
    92     | Intro => Pretty.str (prfx "intro")
    93     | IntroIff => Pretty.str (prfx "introiff")
    94     | Elim => Pretty.str (prfx "elim")
    95     | Dest => Pretty.str (prfx "dest")
    96     | Solves => Pretty.str (prfx "solves")
    97     | Simp pat => Pretty.block [Pretty.str (prfx "simp:"), Pretty.brk 1,
    98         Pretty.quote (Syntax.pretty_term ctxt (Term.show_dummy_patterns pat))]
    99     | Pattern pat => Pretty.enclose (prfx " \"") "\""
   100         [Syntax.pretty_term ctxt (Term.show_dummy_patterns pat)])
   101   end;
   102 
   103 
   104 
   105 (** queries **)
   106 
   107 type 'term query = {
   108   goal: thm option,
   109   limit: int option,
   110   rem_dups: bool,
   111   criteria: (bool * 'term criterion) list
   112 };
   113 
   114 fun map_criteria f {goal, limit, rem_dups, criteria} =
   115   {goal=goal, limit=limit, rem_dups=rem_dups, criteria=f criteria};
   116 
   117 fun xml_of_criterion (Name name) = XML.Elem (("Name", [("val", name)]), [])
   118   | xml_of_criterion Intro = XML.Elem (("Intro", []) , [])
   119   | xml_of_criterion IntroIff = XML.Elem (("IntroIff", []) , [])
   120   | xml_of_criterion Elim = XML.Elem (("Elim", []) , [])
   121   | xml_of_criterion Dest = XML.Elem (("Dest", []) , [])
   122   | xml_of_criterion Solves = XML.Elem (("Solves", []) , [])
   123   | xml_of_criterion (Simp pat) = XML.Elem (("Simp", []) , [XML_Syntax.xml_of_term pat])
   124   | xml_of_criterion (Pattern pat) = XML.Elem (("Pattern", []) , [XML_Syntax.xml_of_term pat]);
   125 
   126 fun criterion_of_xml (XML.Elem (("Name", [("val", name)]), [])) = Name name
   127   | criterion_of_xml (XML.Elem (("Intro", []) , [])) = Intro
   128   | criterion_of_xml (XML.Elem (("IntroIff", []) , [])) = IntroIff
   129   | criterion_of_xml (XML.Elem (("Elim", []) , [])) = Elim
   130   | criterion_of_xml (XML.Elem (("Dest", []) , [])) = Dest
   131   | criterion_of_xml (XML.Elem (("Solves", []) , [])) = Solves
   132   | criterion_of_xml (XML.Elem (("Simp", []) , [tree])) = Simp (XML_Syntax.term_of_xml tree)
   133   | criterion_of_xml (XML.Elem (("Pattern", []) , [tree])) = Pattern (XML_Syntax.term_of_xml tree)
   134   | criterion_of_xml tree = raise XML_Syntax.XML ("criterion_of_xml: bad tree", tree);
   135 
   136 fun xml_of_query {goal=NONE, limit, rem_dups, criteria} =
   137       let
   138         val properties = []
   139           |> (if rem_dups then cons ("rem_dups", "") else I)
   140           |> (if is_some limit then cons ("limit", Markup.print_int (the limit)) else I);
   141       in
   142         XML.Elem (("Query", properties), XML_Data.make_list 
   143           (XML_Data.make_pair XML_Data.make_bool (single o xml_of_criterion)) criteria)
   144       end
   145   | xml_of_query _ = raise Fail "cannot serialize goal";
   146 
   147 fun query_of_xml (XML.Elem (("Query", properties), body)) =
   148       let
   149         val rem_dups = Properties.defined properties "rem_dups";
   150         val limit = Properties.get properties "limit" |> Option.map Markup.parse_int;
   151         val criteria = XML_Data.dest_list (XML_Data.dest_pair XML_Data.dest_bool 
   152           (criterion_of_xml o the_single)) body;
   153       in
   154         {goal=NONE, limit=limit, rem_dups=rem_dups, criteria=criteria}
   155       end
   156   | query_of_xml tree = raise XML_Syntax.XML ("query_of_xml: bad tree", tree);
   157 
   158 
   159 
   160 (** theorems, either internal or external (without proof) **)
   161 
   162 datatype theorem =
   163   Internal of Facts.ref * thm |
   164   External of Facts.ref * term; (* FIXME: Facts.ref not appropriate *)
   165 
   166 fun fact_ref_markup (Facts.Named ((name, pos), SOME [Facts.Single i])) =
   167       Position.markup pos o Markup.properties [("name", name), ("index", Markup.print_int i)]
   168   | fact_ref_markup (Facts.Named ((name, pos), NONE)) =
   169       Position.markup pos o Markup.properties [("name", name)]
   170   | fact_ref_markup fact_ref = raise Fail "bad fact ref";
   171 
   172 fun xml_of_theorem (Internal _) = raise Fail "xml_of_theorem: Internal"
   173   | xml_of_theorem (External (fact_ref, prop)) =
   174       XML.Elem (fact_ref_markup fact_ref ("External", []), [XML_Syntax.xml_of_term prop]);
   175 
   176 fun theorem_of_xml (XML.Elem (("External", properties), [tree])) =
   177       let
   178         val name = the (Properties.get properties "name");
   179         val pos = Position.of_properties properties;
   180         val intvs_opt = Option.map (single o Facts.Single o Markup.parse_int)
   181           (Properties.get properties "index");
   182       in
   183         External (Facts.Named ((name, pos), intvs_opt), XML_Syntax.term_of_xml tree)
   184       end
   185   | theorem_of_xml tree = raise XML_Syntax.XML ("theorem_of_xml: bad tree", tree);
   186 
   187 fun xml_of_result (opt_found, theorems) =
   188   let
   189     val properties =
   190       if is_some opt_found then [("found", Markup.print_int (the opt_found))] else [];
   191   in
   192     XML.Elem (("Result", properties), XML_Data.make_list (single o xml_of_theorem) theorems)
   193   end;
   194 
   195 fun result_of_xml (XML.Elem (("Result", properties), body)) =
   196       (Properties.get properties "found" |> Option.map Markup.parse_int,
   197        XML_Data.dest_list (theorem_of_xml o the_single) body)
   198   | result_of_xml tree = raise XML_Syntax.XML ("result_of_xml: bad tree", tree);
   199 
   200 fun prop_of (Internal (_, thm)) = Thm.full_prop_of thm
   201   | prop_of (External (_, prop)) = prop;
   202 
   203 fun nprems_of (Internal (_, thm)) = Thm.nprems_of thm
   204   | nprems_of (External (_, prop)) = Logic.count_prems prop;
   205 
   206 fun major_prem_of (Internal (_, thm)) = Thm.major_prem_of thm
   207   | major_prem_of (External (_, prop)) =
   208       Logic.strip_assums_concl (hd (Logic.strip_imp_prems prop));
   209 
   210 fun fact_ref_of (Internal (fact_ref, _)) = fact_ref
   211   | fact_ref_of (External (fact_ref, _)) = fact_ref;
   212 
   213 
   214 
   215 (** search criterion filters **)
   216 
   217 (*generated filters are to be of the form
   218   input: theorem
   219   output: (p:int, s:int) option, where
   220     NONE indicates no match
   221     p is the primary sorting criterion
   222       (eg. number of assumptions in the theorem)
   223     s is the secondary sorting criterion
   224       (eg. size of the substitution for intro, elim and dest)
   225   when applying a set of filters to a thm, fold results in:
   226     (biggest p, sum of all s)
   227   currently p and s only matter for intro, elim, dest and simp filters,
   228   otherwise the default ordering is used.
   229 *)
   230 
   231 
   232 (* matching theorems *)
   233 
   234 fun is_nontrivial thy = Term.is_Const o Term.head_of o Object_Logic.drop_judgment thy;
   235 
   236 (*educated guesses on HOL*)  (* FIXME utterly broken *)
   237 val boolT = Type ("bool", []);
   238 val iff_const = Const ("op =", boolT --> boolT --> boolT);
   239 
   240 (*extract terms from term_src, refine them to the parts that concern us,
   241   if po try match them against obj else vice versa.
   242   trivial matches are ignored.
   243   returns: smallest substitution size*)
   244 fun is_matching_thm doiff (extract_terms, refine_term) ctxt po obj term_src =
   245   let
   246     val thy = Proof_Context.theory_of ctxt;
   247 
   248     fun check_match pat = Pattern.matches thy (if po then (pat, obj) else (obj, pat));
   249     fun matches pat =
   250       let
   251         val jpat = Object_Logic.drop_judgment thy pat;
   252         val c = Term.head_of jpat;
   253         val pats =
   254           if Term.is_Const c
   255           then
   256             if doiff andalso c = iff_const then
   257               (pat :: map (Object_Logic.ensure_propT thy) (snd (strip_comb jpat)))
   258                 |> filter (is_nontrivial thy)
   259             else [pat]
   260           else [];
   261       in filter check_match pats end;
   262 
   263     fun substsize pat =
   264       let val (_, subst) =
   265         Pattern.match thy (if po then (pat, obj) else (obj, pat)) (Vartab.empty, Vartab.empty)
   266       in Vartab.fold (fn (_, (_, t)) => fn n => size_of_term t + n) subst 0 end;
   267 
   268     fun bestmatch [] = NONE
   269       | bestmatch xs = SOME (foldl1 Int.min xs);
   270 
   271     val match_thm = matches o refine_term;
   272   in
   273     maps match_thm (extract_terms term_src)
   274     |> map substsize
   275     |> bestmatch
   276   end;
   277 
   278 
   279 (* filter_name *)
   280 
   281 fun filter_name str_pat theorem =
   282   if match_string str_pat (Facts.name_of_ref (fact_ref_of theorem))
   283   then SOME (0, 0) else NONE;
   284 
   285 
   286 (* filter intro/elim/dest/solves rules *)
   287 
   288 fun filter_dest ctxt goal theorem =
   289   let
   290     val extract_dest =
   291      (fn theorem => if nprems_of theorem = 0 then [] else [prop_of theorem],
   292       hd o Logic.strip_imp_prems);
   293     val prems = Logic.prems_of_goal goal 1;
   294 
   295     fun try_subst prem = is_matching_thm false extract_dest ctxt true prem theorem;
   296     val successful = prems |> map_filter try_subst;
   297   in
   298     (*if possible, keep best substitution (one with smallest size)*)
   299     (*dest rules always have assumptions, so a dest with one
   300       assumption is as good as an intro rule with none*)
   301     if not (null successful)
   302     then SOME (nprems_of theorem - 1, foldl1 Int.min successful) else NONE
   303   end;
   304 
   305 fun filter_intro doiff ctxt goal theorem =
   306   let
   307     val extract_intro = (single o prop_of, Logic.strip_imp_concl);
   308     val concl = Logic.concl_of_goal goal 1;
   309     val ss = is_matching_thm doiff extract_intro ctxt true concl theorem;
   310   in
   311     if is_some ss then SOME (nprems_of theorem, the ss) else NONE
   312   end;
   313 
   314 fun filter_elim ctxt goal theorem =
   315   if nprems_of theorem > 0 then
   316     let
   317       val rule = prop_of theorem;
   318       val prems = Logic.prems_of_goal goal 1;
   319       val goal_concl = Logic.concl_of_goal goal 1;
   320       val rule_mp = hd (Logic.strip_imp_prems rule);
   321       val rule_concl = Logic.strip_imp_concl rule;
   322       fun combine t1 t2 = Const ("*combine*", dummyT --> dummyT) $ (t1 $ t2);
   323       val rule_tree = combine rule_mp rule_concl;
   324       fun goal_tree prem = combine prem goal_concl;
   325       fun try_subst prem =
   326         is_matching_thm false (single, I) ctxt true (goal_tree prem) rule_tree;
   327       val successful = prems |> map_filter try_subst;
   328     in
   329       (*elim rules always have assumptions, so an elim with one
   330         assumption is as good as an intro rule with none*)
   331       if is_nontrivial (Proof_Context.theory_of ctxt) (major_prem_of theorem)
   332         andalso not (null successful)
   333       then SOME (nprems_of theorem - 1, foldl1 Int.min successful) else NONE
   334     end
   335   else NONE
   336 
   337 val tac_limit = Unsynchronized.ref 5;
   338 
   339 fun filter_solves ctxt goal =
   340   let
   341     fun etacn thm i = Seq.take (! tac_limit) o etac thm i;
   342     fun try_thm thm =
   343       if Thm.no_prems thm then rtac thm 1 goal
   344       else (etacn thm THEN_ALL_NEW (Goal.norm_hhf_tac THEN' Method.assm_tac ctxt)) 1 goal;
   345   in
   346     fn Internal (_, thm) =>
   347         if is_some (Seq.pull (try_thm thm))
   348         then SOME (Thm.nprems_of thm, 0) else NONE
   349      | External _ => NONE
   350   end;
   351 
   352 
   353 (* filter_simp *)
   354 
   355 fun filter_simp ctxt t (Internal (_, thm)) =
   356       let
   357         val mksimps = Simplifier.mksimps (simpset_of ctxt);
   358         val extract_simp =
   359           (map Thm.full_prop_of o mksimps, #1 o Logic.dest_equals o Logic.strip_imp_concl);
   360         val ss = is_matching_thm false extract_simp ctxt false t thm;
   361       in
   362         if is_some ss then SOME (Thm.nprems_of thm, the ss) else NONE
   363       end
   364   | filter_simp _ _ (External _) = NONE;
   365 
   366 
   367 (* filter_pattern *)
   368 
   369 fun get_names t = Term.add_const_names t (Term.add_free_names t []);
   370 
   371 (*Including all constants and frees is only sound because
   372   matching uses higher-order patterns. If full matching
   373   were used, then constants that may be subject to
   374   beta-reduction after substitution of frees should
   375   not be included for LHS set because they could be
   376   thrown away by the substituted function.
   377   e.g. for (?F 1 2) do not include 1 or 2, if it were
   378        possible for ?F to be (% x y. 3)
   379   The largest possible set should always be included on
   380   the RHS.*)
   381 
   382 fun filter_pattern ctxt pat =
   383   let
   384     val pat_consts = get_names pat;
   385 
   386     fun check (theorem, NONE) = check (theorem, SOME (get_names (prop_of theorem)))
   387       | check (theorem, c as SOME thm_consts) =
   388          (if subset (op =) (pat_consts, thm_consts) andalso
   389             Pattern.matches_subterm (Proof_Context.theory_of ctxt) (pat, prop_of theorem)
   390           then SOME (0, 0) else NONE, c);
   391   in check end;
   392 
   393 
   394 (* interpret criteria as filters *)
   395 
   396 local
   397 
   398 fun err_no_goal c =
   399   error ("Current goal required for " ^ c ^ " search criterion");
   400 
   401 val fix_goal = Thm.prop_of;
   402 
   403 fun filter_crit _ _ (Name name) = apfst (filter_name name)
   404   | filter_crit _ NONE Intro = err_no_goal "intro"
   405   | filter_crit _ NONE IntroIff = err_no_goal "introiff"
   406   | filter_crit _ NONE Elim = err_no_goal "elim"
   407   | filter_crit _ NONE Dest = err_no_goal "dest"
   408   | filter_crit _ NONE Solves = err_no_goal "solves"
   409   | filter_crit ctxt (SOME goal) Intro = apfst (filter_intro false ctxt (fix_goal goal))
   410   | filter_crit ctxt (SOME goal) IntroIff = apfst (filter_intro true ctxt (fix_goal goal))
   411   | filter_crit ctxt (SOME goal) Elim = apfst (filter_elim ctxt (fix_goal goal))
   412   | filter_crit ctxt (SOME goal) Dest = apfst (filter_dest ctxt (fix_goal goal))
   413   | filter_crit ctxt (SOME goal) Solves = apfst (filter_solves ctxt goal)
   414   | filter_crit ctxt _ (Simp pat) = apfst (filter_simp ctxt pat)
   415   | filter_crit ctxt _ (Pattern pat) = filter_pattern ctxt pat;
   416 
   417 fun opt_not x = if is_some x then NONE else SOME (0, 0);
   418 
   419 fun opt_add (SOME (a, x)) (SOME (b, y)) = SOME (Int.max (a, b), x + y : int)
   420   | opt_add _ _ = NONE;
   421 
   422 fun app_filters thm =
   423   let
   424     fun app (NONE, _, _) = NONE
   425       | app (SOME v, _, []) = SOME (v, thm)
   426       | app (r, consts, f :: fs) =
   427           let val (r', consts') = f (thm, consts)
   428           in app (opt_add r r', consts', fs) end;
   429   in app end;
   430 
   431 in
   432 
   433 fun filter_criterion ctxt opt_goal (b, c) =
   434   (if b then I else (apfst opt_not)) o filter_crit ctxt opt_goal c;
   435 
   436 fun sorted_filter filters theorems =
   437   let
   438     fun eval_filters theorem = app_filters theorem (SOME (0, 0), NONE, filters);
   439 
   440     (*filters return: (number of assumptions, substitution size) option, so
   441       sort (desc. in both cases) according to number of assumptions first,
   442       then by the substitution size*)
   443     fun result_ord (((p0, s0), _), ((p1, s1), _)) =
   444       prod_ord int_ord int_ord ((p1, s1), (p0, s0));
   445   in map_filter eval_filters theorems |> sort result_ord |> map #2 end;
   446 
   447 fun lazy_filter filters =
   448   let
   449     fun lazy_match thms = Seq.make (fn () => first_match thms)
   450 
   451     and first_match [] = NONE
   452       | first_match (thm :: thms) =
   453           (case app_filters thm (SOME (0, 0), NONE, filters) of
   454             NONE => first_match thms
   455           | SOME (_, t) => SOME (t, lazy_match thms));
   456   in lazy_match end;
   457 
   458 end;
   459 
   460 
   461 (* removing duplicates, preferring nicer names, roughly n log n *)
   462 
   463 local
   464 
   465 val index_ord = option_ord (K EQUAL);
   466 val hidden_ord = bool_ord o pairself Name_Space.is_hidden;
   467 val qual_ord = int_ord o pairself (length o Long_Name.explode);
   468 val txt_ord = int_ord o pairself size;
   469 
   470 fun nicer_name (x, i) (y, j) =
   471   (case hidden_ord (x, y) of EQUAL =>
   472     (case index_ord (i, j) of EQUAL =>
   473       (case qual_ord (x, y) of EQUAL => txt_ord (x, y) | ord => ord)
   474     | ord => ord)
   475   | ord => ord) <> GREATER;
   476 
   477 fun rem_cdups nicer xs =
   478   let
   479     fun rem_c rev_seen [] = rev rev_seen
   480       | rem_c rev_seen [x] = rem_c (x :: rev_seen) []
   481       | rem_c rev_seen ((x as (t, _)) :: (y as (t', _)) :: xs) =
   482           if (prop_of t) aconv (prop_of t')
   483           then rem_c rev_seen ((if nicer (fact_ref_of t) (fact_ref_of t') then x else y) :: xs)
   484           else rem_c (x :: rev_seen) (y :: xs)
   485   in rem_c [] xs end;
   486 
   487 in
   488 
   489 fun nicer_shortest ctxt =
   490   let
   491     (* FIXME global name space!? *)
   492     val space = Facts.space_of (Global_Theory.facts_of (Proof_Context.theory_of ctxt));
   493 
   494     val shorten =
   495       Name_Space.extern
   496         (ctxt
   497           |> Config.put Name_Space.names_long false
   498           |> Config.put Name_Space.names_short false
   499           |> Config.put Name_Space.names_unique false) space;
   500 
   501     fun nicer (Facts.Named ((x, _), i)) (Facts.Named ((y, _), j)) =
   502           nicer_name (shorten x, i) (shorten y, j)
   503       | nicer (Facts.Fact _) (Facts.Named _) = true
   504       | nicer (Facts.Named _) (Facts.Fact _) = false;
   505   in nicer end;
   506 
   507 fun rem_thm_dups nicer xs =
   508   xs ~~ (1 upto length xs)
   509   |> sort (Term_Ord.fast_term_ord o pairself (prop_of o #1))
   510   |> rem_cdups nicer
   511   |> sort (int_ord o pairself #2)
   512   |> map #1;
   513 
   514 end;
   515 
   516 
   517 (* print_theorems *)
   518 
   519 fun all_facts_of ctxt =
   520   let
   521     fun visible_facts facts =
   522       Facts.dest_static [] facts
   523       |> filter_out (Facts.is_concealed facts o #1);
   524   in
   525     maps Facts.selections
   526      (visible_facts (Global_Theory.facts_of (Proof_Context.theory_of ctxt)) @
   527       visible_facts (Proof_Context.facts_of ctxt))
   528   end;
   529 
   530 val limit = Unsynchronized.ref 40;
   531 
   532 fun filter_theorems ctxt theorems query =
   533   let
   534     val {goal=opt_goal, limit=opt_limit, rem_dups, criteria} = query
   535     val filters = map (filter_criterion ctxt opt_goal) criteria;
   536 
   537     fun find_all theorems =
   538       let
   539         val raw_matches = sorted_filter filters theorems;
   540 
   541         val matches =
   542           if rem_dups
   543           then rem_thm_dups (nicer_shortest ctxt) raw_matches
   544           else raw_matches;
   545 
   546         val len = length matches;
   547         val lim = the_default (! limit) opt_limit;
   548       in (SOME len, drop (Int.max (len - lim, 0)) matches) end;
   549 
   550     val find =
   551       if rem_dups orelse is_none opt_limit
   552       then find_all
   553       else pair NONE o Seq.list_of o Seq.take (the opt_limit) o lazy_filter filters;
   554 
   555   in find theorems end;
   556 
   557 fun filter_theorems_cmd ctxt theorems raw_query = 
   558   filter_theorems ctxt theorems (map_criteria 
   559     (map (apsnd (read_criterion ctxt))) raw_query);
   560 
   561 fun gen_find_theorems filter ctxt opt_goal opt_limit rem_dups raw_criteria =
   562   let
   563     val assms =
   564       Proof_Context.get_fact ctxt (Facts.named "local.assms")
   565         handle ERROR _ => [];
   566     val add_prems = Seq.hd o TRY (Method.insert_tac assms 1);
   567     val opt_goal' = Option.map add_prems opt_goal;
   568   in
   569     filter ctxt (map Internal (all_facts_of ctxt)) 
   570       {goal=opt_goal', limit=opt_limit, rem_dups=rem_dups, criteria=raw_criteria}
   571     |> apsnd (map (fn Internal f => f))
   572   end;
   573 
   574 val find_theorems = gen_find_theorems filter_theorems;
   575 val find_theorems_cmd = gen_find_theorems filter_theorems_cmd;
   576 
   577 fun pretty_theorem ctxt (Internal (thmref, thm)) = Pretty.block
   578       [Pretty.str (Facts.string_of_ref thmref), Pretty.str ":", Pretty.brk 1,
   579         Display.pretty_thm ctxt thm]
   580   | pretty_theorem ctxt (External (thmref, prop)) = Pretty.block
   581       [Pretty.str (Facts.string_of_ref thmref), Pretty.str ":", Pretty.brk 1,
   582         Syntax.unparse_term ctxt prop];
   583 
   584 fun pretty_thm ctxt (thmref, thm) = pretty_theorem ctxt (Internal (thmref, thm));
   585 
   586 fun gen_print_theorems find ctxt opt_goal opt_limit rem_dups raw_criteria =
   587   let
   588     val start = Timing.start ();
   589 
   590     val criteria = map (apsnd (read_criterion ctxt)) raw_criteria;
   591     val (foundo, theorems) = find
   592       {goal=opt_goal, limit=opt_limit, rem_dups=rem_dups, criteria=criteria};
   593     val returned = length theorems;
   594 
   595     val tally_msg =
   596       (case foundo of
   597         NONE => "displaying " ^ string_of_int returned ^ " theorem(s)"
   598       | SOME found =>
   599           "found " ^ string_of_int found ^ " theorem(s)" ^
   600             (if returned < found
   601              then " (" ^ string_of_int returned ^ " displayed)"
   602              else ""));
   603 
   604     val end_msg = " in " ^ Time.toString (#cpu (Timing.result start)) ^ " secs";
   605   in
   606     Pretty.big_list "searched for:" (map (pretty_criterion ctxt) criteria) ::
   607     Pretty.str "" ::
   608     (if null theorems then [Pretty.str ("nothing found" ^ end_msg)]
   609      else
   610       [Pretty.str (tally_msg ^ end_msg ^ ":"), Pretty.str ""] @
   611         map (pretty_theorem ctxt) theorems)
   612   end |> Pretty.chunks |> Pretty.writeln;
   613 
   614 fun print_theorems ctxt =
   615   gen_print_theorems (filter_theorems ctxt (map Internal (all_facts_of ctxt))) ctxt;
   616 
   617 
   618 (** command syntax **)
   619 
   620 local
   621 
   622 val criterion =
   623   Parse.reserved "name" |-- Parse.!!! (Parse.$$$ ":" |-- Parse.xname) >> Name ||
   624   Parse.reserved "intro" >> K Intro ||
   625   Parse.reserved "introiff" >> K IntroIff ||
   626   Parse.reserved "elim" >> K Elim ||
   627   Parse.reserved "dest" >> K Dest ||
   628   Parse.reserved "solves" >> K Solves ||
   629   Parse.reserved "simp" |-- Parse.!!! (Parse.$$$ ":" |-- Parse.term) >> Simp ||
   630   Parse.term >> Pattern;
   631 
   632 val options =
   633   Scan.optional
   634     (Parse.$$$ "(" |--
   635       Parse.!!! (Scan.option Parse.nat -- Scan.optional (Parse.reserved "with_dups" >> K false) true
   636         --| Parse.$$$ ")")) (NONE, true);
   637 in
   638 
   639 val query_parser = Scan.repeat (((Scan.option Parse.minus >> is_none) -- criterion));
   640 
   641 val _ =
   642   Outer_Syntax.improper_command "find_theorems" "print theorems meeting specified criteria"
   643     Keyword.diag
   644     (options -- query_parser
   645       >> (fn ((opt_lim, rem_dups), spec) =>
   646         Toplevel.no_timing o
   647         Toplevel.keep (fn state =>
   648           let
   649             val ctxt = Toplevel.context_of state;
   650             val opt_goal = try (Proof.simple_goal o Toplevel.proof_of) state |> Option.map #goal;
   651           in print_theorems ctxt opt_goal opt_lim rem_dups spec end)));
   652 
   653 end;
   654 
   655 end;